This invention relates to a novel method of applying adjuvants to clothing in tumbler-type drying machines and to compositions of matter and articles suitable for use with the method.
It has been customary for many years to include various adjuvants in detergents and wash-cycle additives. Germicides, fabric softeners and optical brighteners are among the most common such adjuvants used. However, other materials, such as ironing aids, antistatic agents, stain repellents, soil release agents, wrinkle preventatives, deodorizers, fresheners (e.g., perfumes, etc.), cleaning agents, surfactants, flameproofing agents, mothproofing agents, bleaching agents, etc. are also products which potentially can be applied to fabrics employing the method of the present invention. A particular advantage of the present invention is that it is possible to obtain much more efficient and convenient application of the adjuvant to the clothing than can be obtained if the adjuvant is applied in the wash or rinse cycles.
In the wash or rinse cycles, the primary objective is to remove soil, etc. from the cloth being washed by means of detergents, water and emulsifying agents. The presence of detergents and emulsifying agents effective to remove soil from the cloth manifestly renders difficult and less efficient the concurrent application of adjuvants such as fabric softeners or other adjuvants to the same piece of material. Since in the drying cycle following washing and rinsing, the conditions characteristic of the rinsing and washing cycles leading to inefficient application of the fabric adjuvants are not present, there is the potential for the much more efficient utilization and application of such adjuvants.
Due to the heat and mechanical action and residual water on the fabrics in the dryer, it might be expected that fabric adjuvants could be easily and uniformly applied in the dryer. Experience demonstrates, however, that this does not readily occur. For example if clothing to be treated with a fabric softening agent is placed into a dryer together with a pure fabric softening active ingredient such as distearyl dimethyl ammonium chloride, the softener will be somewhat spread throughout the clothing treated, but it will be far from uniformly spread. This may result in unsightly spots on cloth or lead to water repellency. While the problem of nonuniformity of spreading may be alleviated in repeated applications of the adjuvant, more preferable results are obtained if the adjuvant is combined with a distributing agent.